The invention relates to a rotary-anode X-ray tube comprising an anode disc having a body which comprises two rotationally-symmetrical, interconnected parts which are adjacently situtated in the direction of the axis of rotation, a first part thereof being made of molybdenum or a molybdenum alloy whilst a second part is made of graphite, the volume of the second part amounting to at least one half of the volume of the first part.
A rotary-anode X-ray tube of this kind is known from DE-AS No. 21 17 956, FIG. 5, from DE-OS No. 30 13 441 corresponding to Bristish Patent No. 2,073,945 and from EP-OS No. 37 956. The graphite part and the molybdenum part thereof are interconnected by way of soldering, the outer diameter of the connection zone corresponding to the outer diameter of the first part and being larger than the diameter of the focal path. The volume of the graphite part must then amount to at least one half of the volume of the molybdenum part in order to achieve a substantially higher thermal loadability.